The present invention relates to a fastener for fixing an airbag-anchor portion of a curtain airbag to a body panel of an automobile or other vehicle.
Japanese Patent Laid-Open No. 2002-104127 discloses a structure for fixing a head-protecting curtain airbag to a body panel of an automobile. For fixing the curtain airbag, a fastener comprising a knob member, a shank and an engagement member is prepared, and an engagement hole for receiving the engagement member is formed in the body panel. After the engagement member and the shank of the fastener are inserted into the respective mounting holes of an airbag-anchor portion of the curtain airbag and the body panel, the knob member is rotated to fix the curtain airbag to the body panel. The fixing operation can be completed without using a tool. However, the fastening force of this fastener is not high, because the airbag-anchor portion is fixed to the body panel by clamping the body panel and the airbag-anchor portion between the engagement member and the knob member. Since an activated airbag is rapidly deployed and the fastener takes a strong reaction force therefrom, an insufficient fastening force is likely to result in undesirable damage to the fixing structure.
In another known fixing structure for a curtain airbag, a nut is welded to a body panel, and an airbag-anchor portion of the curtain airbag is fixed with a bolt threaded into the nut. While this structure provides a high fastening force, it requires welding the nut to the body panel, and such an additional operation is contrary to operational simplification in automobile assembling lines. Further, in the fixing operation, before the curtain airbag is permanently fixed, it is temporarily fixed to the body panel in order to locate the curtain airbag at a predetermined position, and a special structure is required for the temporary fixing operation.
Screw grommets disclosed in Japanese Utility Model Laid-Open Nos. 62-166309, 62-77308 and Japanese Patent Laid-Open No. 1-216109 are intended to connect first and second panels. Each screw grommet has a shank adapted to be inserted into a mounting hole of one of the panels, and a flange having a size larger than the mounting hole. The shank is formed with a hole for allowing a tapping screw to be driven thereinto through an opening in the flange. A screw grommet can be attached to the first panel by inserting the shank into the mounting hole of the first panel and clamping the first panel between an engagement portion of the shank and the flange. After the second panel is held at a position where the mounting hole of the second panel is aligned with the opening of the flange, the tapping screw is driven into the mounting hole of the second panel and the hole of the screw grommet. In these references there is no suggestion of applicability of their screw grommets to the fixing of a curtain airbag, and there is no mention of the need for coping with the reaction on the fastener caused by sudden expansion of an activated airbag.